dangerous BSA Supersport

[craig9mm]

a friend was given the above.On the outside the stock,aircylinder look vgc,altho barrel a bit tatty
I said I would put a scope on it,and zero it in for him . I tried cocking the gun but it would not cock. I assume the sear not engaging.
A third attempt it cocked but went off when the barrel was closed. No pellet in as I had a feeling this was going to happen
Definetly felt odd,at the end of the cocking stroke .Cant think of a word to desribe it. Very Gritty?
Its a Brum model. I suspect someone has been messing about trying to lighten the trigger pressure
As best as I can see the grubscrew in the trigger blade is there but I havent found an allen key to fit. I have a lot of keys and did lighten a S/S trigger several years ago
I wonder if the grub screw is damaged, amongst anything else
I havent stripped the gun down yet . Cant says I want to but Ive known the new owner years and he isnt in the best state to do it himself
I asked him re prev owner,an elderly chap unlikely to mess with it but someone clearly has bodged this v badly
I much rather shoot than dabble..
Any suggestions?
atb
craig

[evert]

Take it all apart, clean it, look for wear or modfications to the sear surfaces.
It they look ok, reassemble, but add some sears spring tension, then try it again, and try to deliberately provoke the discharge.

[WebleyWombler]

Find an Allen key that fits first and try to adjust the trigger. if that works, Chrono it and see whether it actually needs a strip

[ZAKDINGEL]

As above try the trigger adjustment first it might have just been adjusted to fine and maybes this was the reason for giving it away ??? But sounds like it wouldn't mind a strip and clean new lubes etc

[averageplinker]

Also check to see if the barrel has been bent upwards by accidental discharge whilst the action was broken.
Rich.

[Shed tuner]

I get what the guys are saying about possibly not needing a strip, but whenever I get a new-to-me springer, I strip and service as a matter of course.

They are easy to work on (I'm talking convertional guns here not exotics like GISS / sledge / schmeiser / annie 250s etc) and problems may not be immediately obvious just from shooting them. THis may prevent more serious problems developing, and gives you a good known baseline, and a level of confidence in your kit.

As evert's post, in this instance I'd just NEED to know that the sears hadn't been reground / modified / worn, even if an adjustmnet appeared to solve the problem, to have any real confidence in the safety of the gun.

[craig9mm]

Ive no other SS to compare but even uncocked the trigger travel 5-6mm seems quite heavy which I find suprising
The allen key I suspect I prev used yrs back on a SS, .5mm or even 1mm don't engage the grub screw that affects trigger pressure

[piggy589]

A rudimentary trigger, and people will tamper,particularly trying to lighten it by reducing the sear engagement.

[Phil Russell]

Ive no other SS to compare but even uncocked the trigger travel 5-6mm seems quite heavy which I find suprising
The allen key I suspect I prev used yrs back on a SS, .5mm or even 1mm don't engage the grub screw that affects trigger pressure

Can you get to see the grub screw head... an eyeglass may help. Or could it be imperial? I guess it is not a slot head one?
Sorry if questions are daft ... just thoughts.
Cheers, Phil

[piggy589]

Ive no other SS to compare but even uncocked the trigger travel 5-6mm seems quite heavy which I find suprising
The allen key I suspect I prev used yrs back on a SS, .5mm or even 1mm don't engage the grub screw that affects trigger pressure

The trigger housing is integral and may be splayed allowing a pivot pin to dislocate.

[SRV1]

Being as the cocking stroke seems strange and gritty towards end of stroke, a strip would probably be the right course of action to find what the hell is going on, especially for safety and peace of mind.

Best regards to all...

[rapidresponse1]

hope you get it sorted bud

[greenwayjames]

Ive no other SS to compare but even uncocked the trigger travel 5-6mm seems quite heavy which I find suprising

You dont feel that when shooting the rifle. That heavy longish movement is for the trigger mechanism locking up and sear engaging with the piston. It has to be a strong spring to make sure it all locks up safely after the piston has completed its "over travel". Probably the dangerous person who over adjusted the trigger has caused the dangerous situation. The other possible source of trouble could be if the mainspring is broken and preventing the piston from making the necessary overtravel for the trigger components to lock up correctly?

[metalmickey]

I would suggest stripping it down and check it over for missing / damaged / worn parts, If this was a well used gun they often suffered from wear to the piston and sear profiles, a common cause of not latching up securely on cocking the gun and premature discharge when closing the barrel.

[Phil Russell]

If you decide to strip the rifle:
I am pretty sure that the SuperSport trigger is the same as the Superstar. If it is not, I am sure someone will correct me... but if it is, then read on.
To get the piston out, you either have to dismantle the trigger to allow the piston to pass over the sear or you need to compress the sear enough to allow the piston to pass over it. Dismantling the trigger is easy, re-assembly is not so easy. Compressing the sear out of the way is much easier once you know how/get the knack.
I have posted on here how to do it but if you cannot find the post (it referred to the Superstar) then drop me a PM and I will send my notes in Word form.
Cheers, Phil
PS: Superstar post at 2/11/20 More BSA Superstar observations, trigger trick is towards the end of the topic.